Load transfer device



May 2 1950 R. c. Yl-:oMAN

LOAD TRANSFER DEVICE Filed Maron 19, 1945 Patented May 2, 1950 4NITEDSTATES .PATENT ,QFFICl- Texas Foundries, `tion oi Texas ApplicationMarch 19, 1%5, Serial No. 583,500

This invention relates to load transfer devices and more particularly todevices for transmitting loads between adjacent slabs of concrete` orthe like. p One of the objects of the invention is to provide a loadtransfer device which will` maintain the slabs in vertical alinement andwhich will limit relativeseparation of the slabs. j

Another Objectis to provide a load transfer device made up ofcomplementary members to be imbedded in the slabs respectively and whichare connected for relative movement through one or more pins.

Still another object is to provide a load transfer device in whichyielding material is arranged between the pins and the members tocushion relative movement thereof.

A. further Objectis to provide a load transfer member in the form of asinuous strip having its rebent portions` so arranged that they willinterlock. with complementary portions of adjacent strips.

The above and other objects and advantages will be more readily apparent`from the "following description when read in connection accompanyingdrawing in which- Figure 1 is a partial vertical section through a pairof adjacent slabs connected by a load transfer device embodying theinvention;

Figure 2 is a partial horizontal section on line 2 2 of Figure l;

Figure 3 is a perspective view of a part oi one of the strips; Figure 4is a view similar to Figure l of an alternative construction; and

Figure 5 is a horizontal section on the line 5-5 of Figure 4.

As shown in Figures l and 2, adjacent slabs Il! and Il of concrete orthe like are arranged with a iiller strip I2 between their adjacentfaces to close the space therebetween against ingress oi water or thelike. The filler strip I2 may be made of any desired type of yieldingmaterial such as asphalt saturated felt, compressed wood or metal licexpansion joint structures. ller strip is formed by two separate stripsspaced apart in the central portion of the slab to leave a space throughwhich load transfer devices may extend.

The slabs are connected by a load transfer mechanism including identicalmetallic strips i3. The strips I3 are formed of relatively flatelongated strips of metal sinuously bent to provide rebent portions i4and IE. The rebent portions I4 along one side of the member are formedwith clanes.

with `the the i Preferably the (ci. sii-L) central slots I6 and theportions l5 are reduced in' Width to substantially the same widthas theslots.`"Preferably the portions I-t'a are slightly narrowerthanthe'slots so that they will enter the "slots ina complementarymember snugly. Vertical movement is thus held to minimum withoutpreventing the limited horizontal movement.

shown, the rebent portion Id of one member projects from one of theslabs while the narrow portion i 5 of the other member projects from thethrough'the slots I5 to define vertical openings between the members.With this construction, a

vertical load oneitherof the slabsl will be transmitted to the otherslab through interengagement of the rebent portions I5 with the sides ofthe slots I6. In this way the slabs are maintained in the same plane sothat they will provide a smooth upper surface.

To limit separation of the slabs, pins Il of smaller diameter `than theopenings between the members'aremounted in the openings' and preferablyhave enlarged heads l to limit movement thereof through the openings. Inorder to cushion the relative movement between the slabs and memberssleeves I9 of yielding material, such as rubber or asphalt compositions,'are arranged around the pins substantially to iill the openings.HAsbthe'slab faces tend to separate when the slabs contract under lowtemperatures, the members I3 tend to move apart to reduce the size ofthe openings dened by the rebent portions lli and l5. This actionsqueezes the yielding material I9 and if continued to a suflicientextent will squeeze the yielding material to the extent of itscompressibility or may actually cause the rebent portions of the membersto engage the metal pins i1. At this time, further separation of theslab faces will be prevented so that the slabs cannot move out ofcontact with the ller strips i2 to break the seal at the joint. It willbe understood that the filler strips and load transrer members are sodesigned that they will ac commodate the maximum expected separation ofthe slab faces in response to changes of atmospheric conditions.

To provide for movement of the slab faces toward each other when theslabs expand, yielding plastic material 2D such as rubber, asphaltcomposition or the like is placed between the projecting portions of thestrips and the opposite slab faces. This material may be placed in anydesired manner but is advantageously secured to the strips to be heldproperly in place during installation. When the concrete is in plasticform the material 20 holds it out of direct contact with the metal ofthe strips and will yield when the slabs expand to permit their adjacentfaces to move closer together.

Another construction embodying the invention is illustrated in Figures 4and 5 for connecting adjacent slabs of concrete 2| and 22 which have anexpansible iiller strip 23 between their adjacent faces, In thisConstruction, identical plate members 24 are imbedded in the slabs in avertical position and may if desired be formed with openings 25therethrough to assist in anchoring them in the slabs. The openings maybe formed by partially punching out portions of the plates to leaveanchoring ns as shown. The edge portions of the plates project beyondthe respective slab faces and interfit as shown in Figure 4 so that theywill transmit vertical loads between the slabs to maintain the uppersurfaces thereof in the same piane.

In order to limit separation of the sla-b face the serrations on theprojecting edges of the slabs are rolled around as shown at 26 to formregistering openings through the serrations. A

pin 2l of smaller diameter than the openings extends through theopenings and is preferably surrounded by a sleeve 28 of yieldingmaterial which substantially nlls the openings. Move ment of the slabfaces together is provided for as in Figures 1 and 2 by yielding plasticmaterial 29 overlying the outer ends of the serrations.

In use this construction operates in substantially the same manner asthat of Figures 1 to 3. As the slab faces tend to separate the yieldingmaterial 29 will be squeezed until it has been compressed to its maximumextent or until the serrations Ee engage the pin 2l after which nofurther separation of the slab faces is possible.

While two embodiments of the invention have been shown and described indetail herein, it will be understood that these are illustrative onlyand are not intended as definition of the scope of the invention,reference being had for this purpose to the appended claims.

What is claimed is:

1. In combination with adjacent slabs of concrete or the like a loadtransfer device comprising a pair of sinuous strips imbedded in theslabs respectively with angularly rebent portions thereof projectingbeyond the faces of the slabs, part of the projecting portions beingformed with central slots therethrough and the other rebent portionsbeing of a width to extend through the slots to define openings betweenthe strips, and pins of smaller diameter than the openings tting throughthe openings.

2. In combination with adjacent slabs of concrete or the like a loadtransfer device comprising a pair of sinuous strips imbedded in theslabs respectively with angularly rebent portions thereof projectingbeyond the faces of the slabs, part of the projecting portions beingformed with central slots therethrough and the other rebent portionsbeing of a width to extend through the slots to define openings'betweenthe strips, pins of smaller diameter than the openings tting through theopenings, and sleeves of yielding material around the pins substantiallylling the openings.

3. In combination with adjacent slabs of concrete or the like a load.transfer device comprising a pair of sinuous strips imbedded in theslabs respectively with angularly rebent portions thereof projectingbeyond the faces oi the slabs, part of the projecting portions beingformed with central slots therethrough and the other rebent portionsbeing of a width to extend through the slots to dei-lne openings betweenthe strips, and

pins oi" smaller diameter than the openings iitv ting through theopenings, the outer surfaces of the rebent portions being covered withyielding plastic material.

RAY CYRUS YEOMAN.

REFERENCES CITED The ioilowing references are of record in the lile ofthis patent:

UNITED STATES PATENTS Number Name Date 951,911 Lambert Mar. 1, 19101,393,699 Purcell Oct. ll,` 1921 1,859,664 Fulda May 24, 1932 1,975,281Lumb Oct. 2, 1934 2,103,894 Bussrnann Dec. 28, i937 2,125,857 FischerAug. 2, 1938 2,166,220 Older July 18, 1939 2,280,455 Seuberling Apr. 21,1942 2,319,049 Fischer' May 11, 1943 FOREIGN PATENTS Number Country Date778,683 France 1935

